The printer is showing the message "Check the heatbreak thermistor wiring for possible damage."
Error name: Heatbreak MAXTEMP Error
Error code: #13212 (MK4) #21212 (MK3.9)
The error is shown when the heatbreak thermistor measures over 100 ºC at any point.
Access the LoveBoard. Check if the thermistor is connected correctly and if there is no damage along the cable length.
If you have a multimeter, it is possible to check the resistance of the cables to verify if they are damaged. For that, use our Multimeter usage guide.